This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. SPECIFIC AIMS: By studying male and female healthy controls and irritable bowel syndrome (IBS) patients, the purposes of this study are: 1) to determine if females and males differ in hypothalamic-pituitary-adrenal (HPA) axis responsiveness and sympathetic nervous system (SNS) activation, 2) to correlate these findings with markers of colonic tissue inflammation and cytokine profiles, and 3) to determine if colonic tissue alterations are related to sex-related differences in visceral pain sensitivity.